In conventional processors, while transistors (e.g., metal-oxide semiconductor field effect transistors (MOSFETs)) that form an integral part of a processor work at speeds up to the limit of their cutoff frequency (fcutoff), the processors themselves work significantly slower (e.g., typically two orders of magnitude) than the transistors. For example, operational speed of transistors (MOSFET) in a processor is approximately 100-300 GHz, while the operational speed (clock rate) of the processor is about or below 3 GHz. Even though a new generation of transistors and processors are produced every two years (following, so far, Moore's law), the speed of the processors have continued to remain significantly slower than the operational speed of the underlying transistors that form the processors.
The slower operational speed of conventional processors 100 can be attributed to metal interconnect wires 108 that occupy most of the processor volume as illustrated in FIG. 1B. Further, as illustrated in FIG. 1A, conventional processors are built on CMOS technology where the drive (output) current of one transistor electrostatically charges an interconnect wire and the gate of the complementary transistor. In particular, FIG. 1A illustrates configuration of an example transistor pair of a processor 100 comprising a first transistor 102 that electrostatically charges the interconnect copper wire 106 which in turn charges the gate of the second transistor 104. This electrostatic charging of an interconnect wire in a processor limits the processor speed at least due to an effect of the resistance (R) and capacitance (C) of the interconnect wire. In particular, the resistance and capacitance of the interconnect wire defines the maximum achievable processor speed as f=1/RC. Accordingly, by using standard expressions for resistance and capacitance as shown in Equation 1, standard expression for maximum achievable processor speed as shown in Equation 2, and substituting realistic values for the parameters of the Equation 1 and Equation 2, it can be observed that the maximum achievable processor speed is much slower than the intrinsic transistor speed fcutoff.
                                          C            =                                          ɛ                ⁢                                                                  ⁢                L                                            2                ⁢                ln                ⁢                                                                  ⁢                                  L                  A                                                              ,                      R            =                          L                              π                ⁢                                                                  ⁢                σ                ⁢                                                                  ⁢                                  a                  2                                                                    ⁢                                  ⁢        and                            (        1        )                                          f          RC                =                  1          RC                                    (        2        )            
For example, in the above-mentioned Equation 1, L which is the interconnect wire length can be realistically set as 1 mm, ‘a’ which is its radius of the interconnect wire can be realistically set as 10 nm, ε˜8 is the permittivity of the surrounding material in the processors (average that of silicon (11.9) and silicon dioxide (3.9)), and σ˜6×107 Mho/m is the conductivity of copper. On the basis of the values of each parameter provided above, the maximum achievable processor speed can be derived to be 2.4 GHz which is close to that of actual processors [Pasricha, S. & Dutt, N. On-chip Communication Architectures: System on Chip Interconnect (Morgan Kaufmann, 2008)] and two orders of magnitude smaller than the intrinsic transistor speed, which is approximately 100-300 GHz.
Further, currently, the speed of conventional processors are not defined by maximum transistor speed, i.e., the cutoff frequency fcutoff of the transistor because fcutoff>>fRC, which makes the cutoff frequency irrelevant for defining the processor speed. Instead, the technical descriptions define the processor speed based on the output or drive current of the transistor, i.e., Id˜1 μA per nm of the gate width of the transistor, which for typical 30 nm gate yields Id˜30 μA [Packan, P. et al. High performance 32 nm logic technology featuring 2nd generation high-k+metal gate transistors, in: 2009 IEEE International Electron Devices Meeting (IEDM) 1-4 (2009)]. The drive current may define the processor speed because it the drive current of the underlying transistor that charges of the interconnect wire to a potential difference ΔU˜0.25 V, which is needed to control the complimentary transistor in the processor (e.g., in processors where transistors work in pairs). This limits the processor's maximum speed to [Krausz, F. & Stockman, M. I. Attosecond metrology: from electron capture to future signal processing. Nature Photonics doi: 10.1038/nphoton.2014.28 (2014)]:fmax=Id/(C ΔU)˜3 GHz,  (3)which is close to the maximum actual processor speed of contemporary processors [Pasricha, S. & Dutt, N. On-chip Communication Architectures: System on Chip Interconnect (Morgan Kaufmann, 2008)].
The significant slowing down of the processor speed, e.g., by two orders of magnitude with respect to the transistor speed, fcutoff, results in a commensurate decrease of the energy efficiency of the processor by the same factor. Further, the decrease in the energy efficiency of the processor can also be attributed to the fact that the electrostatic energy stored in interconnect wires are wasted when the transistors switch because only energy which is stored in the orders of magnitude smaller (than that of the wires) gate capacitance of the transistor (e.g., MOSFET) is useful because it defines the drive current, and consequently, the transistor and processor functionalities. As a result, conventional processors have a high heat production per operation. Accordingly, there exists a need for technology that can overcome the above-mentioned shortcomings and improve an operational speed of the conventional processors.